The seasonal variations in the nematode egg counts of sheep: a comparison of the spring rise phenomenon in breeding and unmated ewes

Abstract

Extract Various aspects of the seasonal fluctuations of worm egg counts in sheep have claimed the attention of many workers and, in particular, a number of detailed studies have been undertaken to examine the phenomenon designated the spring rise or post-parturient rise which occurs in sheep each year with apparent unfailing regularity. These studies have been reviewed by Crofton ( 1954 Crofton, H. D. 1954. Parasit., 44: 466–466. [Google Scholar] ), Soulsby ( 1962 Soulsby, E. J. L. 1962. Animal Health and Production, London: Butterworths. [Google Scholar] ), and Spedding ( 1962 Spedding, C. R. W. 1962. Brit. vet. J., 118: 461–461. [Google Scholar] ).